JP2749677B2 - Sunscreen emulsified cosmetic - Google Patents

Description

The present invention relates to a sunscreen emulsified cosmetic having excellent storage stability, skin safety and sunburn preventing effect.

[Prior art and its problems]

BACKGROUND ART Hitherto, fine titanium oxide particles or fine titanium oxide particles coated with an oily substance and various synthetic ultraviolet absorbers have been applied to sunscreen cosmetics.

(Japanese Unexamined Patent Publication No. 62-67015, Japanese Unexamined Patent Publication No. 62-145011, etc.) However, emulsified cosmetics containing finely divided titanium oxide so as to sufficiently satisfy the sunburn-preventing effect,
In order to enhance the storage stability, it was necessary to incorporate a surfactant in a high concentration, and this had disadvantages such as poor water resistance, sweat resistance and skin safety.

Similarly, when the synthetic ultraviolet absorber is blended to such an extent that the effect of preventing sunburn is satisfied, the emulsified cosmetic has problems such as poor skin safety.

[Means for solving the problem]

Accordingly, the present inventors have conducted intensive studies to solve the above problems, and as a result, an emulsification obtained by dispersing fine particle titanium oxide by applying a specific bentonite thickener, a polyhydric alcohol and an ester of a fatty acid described later. Type cosmetics have storage stability,
The present inventors have found that they have excellent skin safety and sunburn preventing effects, and have completed the present invention.

That is, the present invention provides a particulate titanium oxide, bentonite containing at least 100 mg equivalent / 100 g of cation exchangeable sodium ion, at least one selected from the group of dextrin fatty acid esters and sucrose fatty acid esters, an oily substance, and water. And a sunscreen emulsified cosmetic composition.

Hereinafter, the configuration of the present invention will be described in detail. The fine particle titanium oxide used in the present invention is a known substance, and its average particle size is preferably 30 to 70 mμ. The fine particle titanium oxide may be oily fine particle titanium oxide surface-treated with an oily substance such as various silicones, higher fatty acids and salts thereof, mineral oils, ester oils, natural fats and oils, and waxes ( JP-A-59-15885, JP-A-61-127767,
See JP-A-62-67015 and JP-A-62-145011). The compounding amount is usually preferably 0.5 to 20% by weight (hereinafter abbreviated as wt%).

The bentonite used in the present invention is sodium montmorillonite, which is a kind of natural colloidal hydrated aluminum silicate, and has a cation exchangeable sodium ion content (Experimental Agricultural Chemistry, Vol. 59-62, Asakura Shoten, It is sufficient that the viscosity of a 4.0 wt% aqueous dispersion of bentonite is 150 to 800 centipoise (B-type rotational viscometer, measurement 20).
C).

This high-purity sodium montmorillonite is obtained from specific veins or by special physical or chemical treatment.

For example, bentonite produced in the Omachi area of Yamagata Prefecture is fractionated and purified to obtain bentonite having various cation exchangeable sodium ion contents, and as described later, as a result of being blended into an emulsified cosmetic, as a result, Bentonite, which has a high sodium ion content and a value of 100 to 160 mg equivalent / 100 g (hereinafter abbreviated as bentonite (Na: 100 to 160)), has excellent water swelling properties, and has a small amount of aqueous phase. It was clearly observed that the viscosity of the components was increased to improve the dispersion of the particulate titanium oxide, and to enhance the storage stability of the sunscreen emulsified cosmetic of the present invention.

In addition, the cation exchangeable sodium inone content of various bentonite used in the section of Examples below, its 4.0w
The viscosity of the t% aqueous dispersion is as follows.

The blending amount of the bentonite is preferably 0.05 to 5.0 wt% based on the total amount of the cosmetic. 0.05wt
%, The storage stability is not sufficient, and 5.0 wt.
%, The appearance characteristics and practical characteristics of the dosage form deteriorate.

The dextrin fatty acid and sucrose fatty acid ester used in the present invention are known substances, and are esterified products of dextrin or sucrose having an average degree of polymerization of 10 to 50 glycol units and various higher fatty acids.

For example, dextrin stearate, dextrin oleate, dextrin isostearate, dextrin palmitate, dextrin myristate, sucrose stearate, sucrose oleate, sucrose palmitate, sucrose myristine Examples thereof include acid esters, but are not limited thereto. The amount of each of the dextrin fatty acid ester and the fatty acid ester such as sho, etc., alone or in combination, is preferably 0.2 to 5.0% by weight (hereinafter abbreviated as wt%) based on the total amount of the cosmetic. If the content is less than 0.2 wt%, the storage stability is poor.
If the amount exceeds wt%, practical properties such as appearance properties and viscosity of the dosage form deteriorate.

By using the bentonite and the dextrin fatty acid ester and / or the sucrose fatty acid ester together, the viscosity of the oil phase and the aqueous phase component is increased, and the dispersibility of the fine particle titanium oxide is improved by the synergistic effect, and the storage stability is improved. It was found to increase.

The oily substance used in the present invention is a known oily raw material for cosmetics and includes, for example, fats and oils, waxes, hydrocarbons, ester oils, higher alcohols, higher fatty acids and the like.

One or more of these oily substances are selected and applied depending on the type, dosage form and purpose of the cosmetic. The amount is usually based on the total amount of the cosmetic.
10-70 wt%.

Water is purified water that is usually used,
Deionized purified water or distilled water treated with an ion-exchange resin is applied, and its blending amount is 20 to 85 based on the total amount.
It is preferably set to wt%.

Furthermore, the sunscreen emulsified cosmetic of the present invention has improved dispersibility and improved various properties (storage stability, sensory properties, etc.) by blending xanthan gum with 0.1 to 2.0 wt% based on the total amount. It was acknowledged to have.

In addition, the sunscreen emulsifying cosmetic of the present invention includes, in addition to the above, a surfactant, a fragrance, a preservative, a humectant, a pigment, a pigment,
Such ordinary ingredients for cosmetics can be appropriately compounded within a range that achieves the object of the present invention.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to examples.

The evaluation methods of characteristic values, such as a storage stability test, a sun protection effect test, and a human skin patch test, described in the Examples are as follows.

Storage stability test After storing the sample in a thermostatic chamber at 45 ° C for 3 months, observe the appearance and emulsified state of the sample. If no abnormality is observed (the emulsified state and the particles are uniform), it is considered good. When abnormalities were observed (such as when oil separated or particles became coarse), it was determined to be defective.

Sunburn prevention effect test Part of the skin on the back of a total of 20 subjects, 10 men and women each
Thirteen sections each having a size of 9 cm ² (3 × 3 cm) were prepared, and the sunscreen cosmetics as test materials were applied to 12 sections at a rate of 2 mg per 1 cm ² . Next, the back of the subject was illuminated with summer seaside sunlight, and the sunlight was completely shielded every ten minutes by one section for a total of two hours.

(1) Measurement of SPF value (Sun Protection Factor) In the above solar irradiation test, the ratio of the minimum erythema generation energy Ea of the site where the sample was applied to the minimum erythema generation energy Ec of the site where the sample was not applied at all. From the following equation.

SPF value = Ea / Ec The irradiation energy of sunlight was measured with an integrated illuminance recording device (PH-11M-2AT) manufactured by Suga Test Instruments Co., Ltd. (The definition of SPF value is defined in Federal Register 43, ( 166), 3
8206-38269 (1978)).

(2) Evaluation of skin erythema and blackening Immediately after irradiation with sunlight for 2 hours, 24 hours, 48 hours, and 72 hours
The state of the skin after time was compared and observed with the naked eye by a doctor. The determination of erythema and darkening of the skin was performed according to the following criteria, and indicated by the average value of the evaluation points of 20 test subjects.

The erythema determination was performed immediately after and 24 hours after irradiation on the one with strong erythema, and the blackening determination was performed on 48 hours and 72 hours after the irradiation with strong blackening, respectively.

Skin safety test (Human skin patch test) A 0.05 g sample was applied to the forearm flexion side skin of 25 subjects with a diameter of 1.0
After 24 hours of occlusive application using a patch test bandage with a cm-shaped lint cloth, the skin condition of 25 subjects was evaluated and measured for each sample according to the following criteria. The result of the determination was the one with the strongest reaction between 1 hour and 24 hours after removal of the adhesive bandage, and the evaluation of the following criteria was indicated by the number of people (±) or more.

Examples 1 to 5 and Comparative Examples 1 to 3 (Sunscreen creams) Each sunscreen cream was purified with the composition shown in Table 1 and various properties were evaluated by the above evaluation methods. The evaluation results are shown in the right columns of Tables 2 and 3.

(1) Composition (2) Preparation method Untreated (water-dispersible) fine particle titanium oxide is dispersed in the component (C), and oily treated (oil-dispersible) fine particle titanium oxide is dispersed in the component (A). C) each component
After heating and melting at 80 ° C, mix at 30 ° C with stirring.
Cooled to prepare each cream.

(3) Characteristics As shown in Tables 2 and 3, the emulsified cosmetic composition of Comparative Example 1 containing another surfactant substance different from the present invention has good storage stability. Even so, skin safety was inferior, and skin irritation erythema was observed in a sunburn prevention effect test.

Further, as in Comparative Examples 2 and 3, when bentonite or dextrin fatty acid and sucrose stearic acid ester were individually added, storage stability was clearly inferior. It was recognized that the sunscreen emulsion cosmetics of Examples 1 to 5 of the present invention were excellent in various properties.

(Effect of the Invention) As described above, the present invention clearly provides a useful sunscreen emulsified cosmetic having excellent properties in all of storage stability, skin safety, and sunscreen prevention effect. It is.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) A61K 7/00 N A61K 7/42

Claims (2)

(57) [Claims] 1. The following a. ~ E. Sunscreen emulsifying cosmetics containing 5 components a. Fine particle titanium oxide b. 100mg equivalent of cation exchangeable sodium ion / 100g
Bentonite contained above. At least one of dextrin fatty acid esters and sucrose fatty acid esters d. Oily substances e. water 2. The method of claim 1, wherein The sunscreen emulsifying cosmetic according to claim 1, wherein xanthan gum is blended in addition to the 5-component.